The present invention relates to a liquid spray device for feeding spray (liquid particulates) in a container to spray liquid to a target object and a cutting method using the same. More particularly, the present invention relates to a liquid spray device for supplying a cutting member of a machine tool, for example, a machining center, a grinding machine, a turning machine, or the like, with a cutting oil and to a cutting method using the same.
Hitherto, during machining, oil is sprayed to a target object, for example, a work piece or a tool, etc., in order to enhance the machining accuracy or to extend the life of tools. In a method of directly spraying liquid oil to the target object, the amount to be sprayed becomes too large, so that it takes a long time to remove excess oil, thus reducing the productivity. Furthermore, since the excess oil scatters around the device, it has been necessary to prevent the working environment from being contaminated.
When oil is sprayed in the form of oil droplets, since a machining operation can be performed with only the necessary minimum amount of oil, it is possible not only to improve the process accuracy or productivity, but also to improve the working environment, thus simplifying plant and equipment. JP5-92596U proposes one example of a device capable of spraying oil in the form of oil droplets.
However, in the above-mentioned oil supplying device, it is necessary to provide a spray producing part with a casing for an oil dropping part, a path for fast-speed gas, a Venturi nozzle, and the like. Furthermore, a pump and an oil vessel are formed separately from the main body, thus making the structure of the spray device complicated.
Furthermore, in the above-mentioned oil supplying device, an internal pressure of the main body is dependent upon a primary supply pressure and a hole diameter (a cross-sectional area) of a tip spray injection part. Consequently, as the hole diameter of the spray injecting part is changed, the internal pressure of the main body changes accordingly. Therefore, when, for example, a tool provided with a discharging port is used as the spray injection part, if the tool is replaced with one having a smaller hole diameter, the internal pressure of the main body is increased. In this case, the flow velocity of spray injection can be secured without any problems. However, since the difference between the primary supply pressure and the internal pressure of the main body is reduced, a sufficient amount of spray may not be produced effectively at a spray production part.
On the contrary, if the tool is replaced with one having a larger hole diameter, the internal pressure of the main body is reduced. In this case, it is possible to secure the difference between the primary supply pressure and the internal pressure of the main body. Therefore, there is no problem in producing spray effectively. However, occasionally, the flow velocity of injection cannot be secured sufficiently. Actually, a number of production plants employ unmanned operation. Therefore, it is impossible to adjust the supply pressure every time the hole diameter of injection is changed.
It is an object of the present invention to provide a liquid spray device capable of reliably producing a fine spray stably with a simple structure and of securing a flow velocity of injecting spray and a cutting method using the same.
In order to attain the above-mentioned object, a first liquid spray device according to the present invention includes a container, a spray injection nozzle for injecting oil spray into the container, a spray feeding path for feeding oil spray in the container to the outside of the container, wherein liquid is stored in the container, and an under-liquid nozzle having a gas exhaust port in the liquid and producing spray by supplying gas into the liquid is provided.
With such a liquid spray device, the use of the under-liquid nozzle can enhance the internal pressure of the container and produce spray in addition to the spray produced by the spray injection nozzle. Thus, it is possible to increase the flow velocity of spray at the exit of the spray feeding path and to increase the amount of spray.
It is preferable in the first liquid spray device that most of the injected spray flow from the spray injection nozzle is allowed to strike the wall face of the container before being fed to the spray feeding path. With such a preferred liquid spray device, since oil spray having a large diameter or oil droplet is easily attached to the wall face, it is possible to prevent the oil spray having a large diameter or oil droplet from entering the spray feeding pipe.
Furthermore, it is preferable that the wall face is a liquid surface of the liquid. With such a liquid spray device, since oil spray having a large diameter or oil droplet is easily absorbed by the liquid surface when striking the liquid surface, it is possible to prevent the oil spray having a large diameter or oil droplet from entering the spray feeding pipe.
Furthermore, it is preferable that the liquid spray device further includes a pressure controlling means for keeping the pressure in the container constant in a path for supplying the gas to the under-liquid nozzle. When the internal pressure of the container is constant, the difference between the primary pressure of the gas supplied to the container and the internal pressure of the container becomes constant, the flow velocity of the gas in the container for spraying is also constant, and thus stable production of spray can be realized. Furthermore, also at the discharging part, since the constant flow velocity can be secured, it is possible to discharge oil spray by converting the oil spray into the oil droplets.
Furthermore, it is preferable that the liquid spray device further includes a gas discharge nozzle having a tip in the air inside the container and discharging gas. With such a liquid spray device, since the internal pressure of the container can be increased, it is possible to increase the flow velocity at the exit part of the spray feeding path.
Furthermore, it is preferable that the liquid spray device further includes a pressure controlling means for keeping the pressure in the container constant for feeding gas into a path for supplying the gas to the gas discharge nozzle. If the internal pressure for feeding gas into the container is constant, the difference between the primary pressure in the container and the internal pressure of the container becomes constant. As a result, the flow velocity of the gas for producing spray in the container is also constant, thus realizing the stable production of spray. Furthermore, it is possible to obtain the constant flow velocity also at the discharge part, and it is possible to discharge spray in the form of oil droplets.
Furthermore, it is preferable that a tip-tapered discharge part is connected to the tip of the spray feeding path. With such a liquid spray device, the flow velocity of spray at the discharge part is increased, and it is possible to take out the spray in the form of oil droplets.
Furthermore, it is preferable that gas and liquid are fed to the spray injection nozzle, and the spray is injected into the container by mixing the gas and the liquid in the spray injection nozzle.
Furthermore it is preferable that the liquid stored in the container flows into a liquid supply means and the liquid discharged from the liquid supply means is fed to the spray injection nozzle. With such a liquid spray device, it is not necessary to provide an oil tank separately, so that it is possible to circulate the liquid in the container effectively.
Furthermore, it is preferable that the liquid supply means is a liquid pump.
Furthermore, it is preferable that the liquid supply means is a siphon tube having the tip portion in the liquid stored in the container and capable of siphoning up the liquid stored in the container.
Furthermore, it is preferable that the liquid spray device further includes a pressure control means for keeping the pressure in the container constant in a path for supplying the gas to the spray injection nozzle. When the internal pressure of the container is constant, the difference between the primary pressure of the gas supplied to the container and the internal pressure of the container is constant, the flow velocity of the gas in the container for spraying is also constant, and thus stable production of spray can be realized. Furthermore, also at the discharge part, the constant flow velocity can be secured, and it is possible to discharge oil spray by converting oil spray into oil droplets.
Next, according to a second liquid spray device of the present invention, the liquid spray device includes a container, a spray injection nozzle for injecting spray into the container, and a spray feeding path for feeding the spray in the container to the outside of the container, wherein most of the injected spray flow from the spray injection nozzle is allowed to strike the wall face in the container before being fed to the spray feeding path.
According to such a liquid spray device, since oil spray having a large diameter or oil droplets are attached easily to the wall face when they strike the wall face, it is possible to prevent the oil spray having a large diameter or oil droplets from entering the spray feeding pipe.
It is preferable in the second liquid spray device that the inside of the container is divided into an upper space and a lower space by the wall face, and the injection port of the spray injection nozzle is located in the lower space.
According to such a liquid spray device, since oil spray having a large diameter or oil droplets are attached easily to the wall face when they strike the wall face, and most of the attached spray and droplets drop to the lower part of the container by gravity. Therefore, most of the spray or droplets fed to the upper space is fine spray. Thus, it is possible to prevent oil spray having a large diameter or oil droplet from entering the spray feeding pipe.
Furthermore, it is preferable that the inside of the container is divided into an upper space and a lower space by the wall face, and the injection port of the spray injection nozzle is located in the upper space.
According to such a liquid spray device, since most of oil spray having a large diameter or oil droplet is attached to the wall face, when it strikes the wall face, most of the attached spray and droplets drop to the lower part of the container by gravity along the wall face. Therefore, most of the spray or droplets fed to the upper space is fine spray. Thus, it is possible to prevent oil spray having a large diameter or oil droplet from entering the spray feeding pipe.
Furthermore, it is preferable that the wall face is the inner wall face of a dome member opening downward. With such a liquid spray device, it is easy to drop spray having a large diameter or droplets to the lower space, that is, a lower part of the container.
Furthermore, it is preferable that the wall face is the outer wall face of a dome member opening downward. With such a liquid spray device, it is easy to drop spray having a large diameter or droplets to the lower space, that is, a lower part of the container.
Furthermore, it is preferable that the wall face is a liquid surface of the liquid stored in the container. With such a liquid spray device, since oil spray having a large diameter or droplets are easily attached to the wall face when they strike the face, it is possible to prevent the oil spray having a large diameter or droplets from entering the spray feeding pipe.
Furthermore, it is preferable that an injected spray flow feeding path is formed on the wall face, and most of the injected spray flow from the spray injection nozzle can be taken out directly to the outside of the container by opening a valve connecting to the injected spray flow feeding path.
With such a liquid spray device, in a case where the screening of the particle size of spray is not required, the injected spray flow from the spray injection nozzle can be taken out to the outside of the container directly.
Furthermore, it is preferable that the injected spray flow, after striking the wall face and before being fed to the spray feeding path, strikes another wall face formed separately from the wall face. With such a liquid spray device, it is possible to prevent the oil spray having a large diameter or oil droplets from entering the spray feeding pipe thoroughly.
Furthermore, it is preferable that the liquid spray device further includes a gas discharge nozzle having a tip in the air inside the container and discharging gas. With such a liquid spray device, since the internal pressure of the container can be increased, it is possible to increase the flow velocity of the spray at the exit part of the spray feeding path.
Furthermore, it is preferable that the liquid spray device further includes a pressure control means for keeping the pressure in the container constant in the path for supplying the gas to the gas discharge nozzle. When the internal pressure of the container for spraying is constant, the difference between the primary pressure of the gas supplied to the container and the internal pressure of the container is constant, the flow velocity of the gas in the container for producing spray is also constant, and thus spray can be produced stably. Furthermore, also at the discharging part, the constant flow velocity can be secured, and it is possible to discharge oil by converting oil spray into the oil droplets.
Furthermore, it is preferable that a tip-tapered discharge part is connected to the tip of the spray feeding path. With such a liquid spray device, the flow velocity is increased at the injection part, so that it is possible to take out oil by converting oil spray into droplets.
Furthermore, it is preferable that gas and liquid are fed to the spray injection nozzle, and the spray is injected into the container by mixing the gas and the liquid in the spray injection nozzle.
Furthermore, it is preferable that the liquid stored in the container flows into a liquid supply means and the liquid supplied from the liquid supply means is fed to the spray injection nozzle. With such a liquid spray device, an oil tank is not provided separately, thus circulating the liquid in the container efficiently.
Furthermore, it is preferable that the liquid supply means is a liquid pump.
Furthermore, it is preferable that the liquid supply means is a siphon tube having a tip portion in the liquid stored in the container and capable of siphoning up the liquid stored in the container.
Furthermore, it is preferable that the liquid spray device further includes a pressure control means for keeping the pressure in the container constant in a path for supplying the gas to the spray injection nozzle. When the internal pressure of the container is constant, the difference between the primary pressure of the gas supplied to the container and the internal pressure of the container is constant, the flow velocity of the gas in the container for producing spray is also constant, and thus spray can be produced stably. Furthermore, also at the discharging part, the constant flow velocity can be secured, and it is possible to discharge oil by converting oil spray into the oil droplets.
Next, according to a third liquid spray device of the present invention, spray in a container passes through the spray feeding path and is fed to the outside of the container by pressure of the gas supplied into the container, and a pressure control means keeps the pressure in the container constant.
With such a liquid spray device, spray having a large diameter can be trapped in the container constantly. The feeding of spray has an excellent fast-response property. It is possible to keep the internal pressure of the container constant. Therefore, the difference between the primary pressure of the gas supplying to the gas and the internal pressure of the container is constant and the flow velocity of gas for producing spray is also constant, and thus spray can be produced stably. Furthermore, since it is possible to obtain the constant flow velocity at the injection part, it is possible to inject the spray in the form of oil droplets and to prevent the flow velocity of the spray from changing. As a result, the amount of discharge spray can be made stable.
It is preferable in the above-mentioned third liquid spray device of the present invention that the spray is injected from the spray injection nozzle for injecting the spray into the container, gas and liquid are fed to the spray injection nozzle, and the spray is injected into the container by mixing the gas and the liquid in the spray injection nozzle.
Furthermore, it is preferable that the liquid spray device includes the pressure control means in the path for supplying the gas to the spray injection nozzle.
Furthermore, it is preferable that liquid is stored in the container, and an under-liquid nozzle having a gas exhaust port in the liquid and producing the spray from liquid by supplying gas to the liquid by the under-liquid nozzle is provided.
Furthermore, it is preferable that the liquid spray device further includes a pressure control means in a path for supplying the gas to the under-liquid nozzle.
Furthermore, it is preferable that the pressure control means has a pressure regulating valve connecting to the gas supplying path, closes the pressure regulating valve to stop supplying the gas when the pressure in the container is increased and reaches a set value, and opens the pressure regulating valve to resume gas supply when the pressure in the container drops to the predetermined pressure. With such a liquid spray device, since the structure is simple, the cost can be minimized, and the attachment work is simplified.
Furthermore, it is preferable that the set value can be changed. Such a liquid spray device can be used in different manners depending upon the applications of use.
Furthermore, it is preferable that the pressure control means has an electromagnetic valve connecting to the gas supplying path and a pressure switch having a pressure detection part located in the container, wherein when the pressure in the container is increased and reaches the upper limit of the set value, the pressure switch closes the electromagnetic valve to stop supplying gas, and when the pressure in the container drops to the lower limit of the set value, the pressure switch opens the electromagnetic valve to re-start to supply the gas. With such a liquid spray device, the operation becomes more reliable, and the accuracy in the pressure control can be enhanced.
Furthermore, it is preferable that the pressure switch has a plurality of combinations of different upper limit set values and lower limit set values and can be switched between the combinations. With such a pressure switch, the device can be used separately for several purposes, for example, for cutting and for air blowing.
Furthermore, it is preferable that the pressure control means has a valve provided in the gas supplying path and a pressure sensor for detecting the pressure of the gas after passing through the valve, and a control part, wherein the detection pressure detected by the pressure sensor is converted into electric signals and the electric signals are processed arithmetically at the control part, and the control part produces a signal to close the valve so as to stop supplying the gas when it judges that the detection pressure reaches the upper limit of the set value, and the control part produces a signal to open the valve so as to resume gas supply when it judges that the detection pressure reaches the lower limit of the set value. With such a liquid spray device, the operation is more reliable, and the accuracy in the pressure control can be enhanced.
Furthermore, it is preferable that the pressure sensor is located in the container.
Furthermore, it is preferable that the pressure sensor is located between the valve and the container in the gas supplying path.
Furthermore, it is preferable that the pressure sensor is located in the spray feeding path.
Furthermore, it is preferable that the upper limit and lower limit set values can be changed. With such a liquid spray device, the device can be used separately for several purposes, for example, for cutting and for air blowing.
Furthermore, it is preferable that a tip-tapered discharging part is connected to the tip of the spray feeding path. With such a liquid spray device, since the flow velocity of spray is increased at the spray discharge part, spray can be taken out in the form of droplets.
Next, according to a first cutting method of the present invention, a cutting method includes attaching a liquid spray device to an oil supplying part of a machine tool, the liquid spray device including a container, a spray injection nozzle for injecting oil spray into the container, a spray feeding path for feeding oil spray in the container to the outside of the container, wherein the oil is stored in the container, and an under-liquid nozzle having a gas exhaust port produces spray by discharging gas into the oil; and cutting the target object to be processed by supplying the spray to a cutting member of the machine tool.
According to the above-mentioned cutting method, since the spray is supplied to the target object to be processed, the spraying amount can be minimized, thus improving the productivity and preventing the operation environment from being contaminated. Furthermore, since the liquid spray device is provided with the under-liquid nozzle, the internal pressure in the container can be increased, and another spray can be produced in addition to the spray from the spray injection nozzle. Therefore, the flow velocity of the spray at the exit part of the spray feeding path can be increased and the amount of spray can be increased.
It is preferable in the above-mentioned first cutting method that most of the injected spray flow from the spray injection nozzle is allowed to strike the wall face of the container before being fed to the spray injection path. According to the above-mentioned cutting method, since spray having a large diameter or droplets are attached easily to the wall face, it is possible to prevent the oil spray having a large diameter or droplets from entering the spray feeding pipe.
Next, according to a second cutting method, a cutting method includes attaching a liquid spray device to an oil supplying part of a machine tool, the liquid spray device including a container, a spray injection nozzle for injecting oil spray into the container, a spray feeding path for feeding oil spray in the container to the outside of the container, wherein most of the spray from the injection nozzle is allowed to strike a wall face in the container before being fed to the spray feeding path; and cutting the target object to be processed by supplying the spray to a cutting member of the machine tool.
According to the above-mentioned cutting method, since the spray is supplied to the target object to be processed, the spraying amount can be minimized, thus improving the productivity and preventing the operation environment from being contaminated. Since spray having a large diameter or droplets are attached easily to the wall face, it is possible to prevent the oil spray having a large diameter or droplets from entering the spray feeding pipe.
It is preferable in the pressure control means has an electromagnetic valve connecting to the gas supplying path and a pressure switch having a pressure detection part located in the container, wherein when the pressure in the container is increased and reaches the upper limit of the set value, the pressure switch closes the electromagnetic valve to stop supplying gas, and when the pressure in the container drops to the lower limit of the set value, the pressure switch opens the electromagnetic valve to resume gas supply. In the second cutting method, the inside of the container is divided into an upper space and a lower space by the wall face, in which the injection port of the spray injection nozzle is located in the lower space. According to the above-mentioned cutting method spray having a large diameter or droplets are attached easily to the wall face. Most of the attached spray or droplets drop by gravity into the lower space, that is, the lower part of the container, so that most of the spray fed to the upper space is fine spray. Thus, it is possible to prevent the spray having a large diameter or droplets from being fed to the spray feeding pipe.
Furthermore, it is preferable that the container is divided into an upper space and a lower space by the wall face, in which the injection port of the spray injection nozzle is located in the upper space.
According to the above-mentioned cutting method, the spray having a large diameter or droplets, when they strike the wall face, are attached to the wall face, or drop along the wall face downward to the lower space. Therefore, most of the spray fed to the upper space of the container is fine spray. It is possible to prevent the spray having a large diameter or droplets from being fed to the spray feeding pipe.
Next, according to a third cutting method of the present invention, a cutting method includes attaching a spray device to an oil supplying part of the machining tool, wherein in the spray device, the spray in the container passes through the spray feeding path and is fed to the outside of the container by a gas pressure of the gas supplied into the container, and a pressure control means for keeping the pressure inside the container constant is provided; and cutting the target object to be processed by supplying a cutting member of the machining tool with the spray.
According to the above-mentioned cutting method, since the spray is supplied to the target object to be processed, the spraying amount can be minimized, thus improving the productivity and preventing the operation environment from being contaminated. With the above-mentioned liquid spray device, spray having a large diameter can be trapped in the container. The feeding of the spray has an excellent fast-response property. It is possible to keep the internal pressure of the container constant. Therefore, the difference between the primary pressure of the gas supplying to the container and the internal pressure of the container is constant and the flow velocity of gas for producing spray is constant, thus realizing the stable production of spray. Furthermore, it is possible to obtain the constant flow velocity at the discharge part, it is possible to inject the spray in the form of the oil droplets and to prevent the flow velocity of the spray from changing. As a result, the amount of discharge spray can be made stable.
It is preferable in the third cutting method that the pressure control means has a pressure regulating valve connecting to the gas supplying path, and wherein the pressure regulating valve is closed so as to stop supplying the gas when the pressure in the container is increased to the set value, and the pressure regulating valve is opened so as to resume gas supply when the pressure in the container drops to the predetermined pressure.
According to the above-mentioned cutting method, the structure of the liquid spray device is simplified, and it is possible to minimize the cost. The attachment operation is easy.
Furthermore, it is preferable that the pressure control means has an electromagnetic valve connecting to the gas supply path and a pressure switch having a pressure detection part located in the container, and wherein the pressure switch closes the electromagnetic valve to stop supplying the gas when the pressure in the container is increased to the set value, and the pressure switch opens the electromagnetic valve to resume gas supply when the pressure in the container drops to the predetermined pressure. As mentioned above, the operation of the liquid spray device can be made reliable, thus enhancing the accuracy of the pressure control.
Furthermore, it is preferable that the pressure control means includes a valve provided in the gas supplying path, a pressure sensor for detecting the pressure of the gas after passing through the valve and a control part, wherein the detection pressure detected by the pressure sensor is converted into electric signals and the electric signals are processed arithmetically at the control part, wherein the control part sends a signal to close the valve so as to stop the gas supply when it judges that the detection pressure reaches the upper limit of the set value, and the control part sends a signal to open the valve so as to resume gas supply when it judges that the detection pressure reaches the lower limit set value. According to the above-mentioned cutting method, it is possible to obtain more reliable operation and to enhance the accuracy in the pressure control.